CBD, also known as cannabidiol, is one of over 100 cannabinoids found in cannabis and is extracted as an oil from both hemp and marijuana. Since CBD is extracted as a stand-alone substance, there's no THC (the psychoactive Cannabidoid responsible for getting the user high) to be found.

Since the user doesn't get high when using CBD oil, it's an extremely favorable substance among people who wish to reap the benefits it has to offer but don't want to smoke medical marijuana.